Hydraulically operated couplers (also known as quick hitches or quick couplers) are well known in the excavator industry and are typically used for coupling an excavator to a range of work attachments or implements. Such attachments would include a tilting bucket, a rock bucket, a trench bucket, a grapple, a hydraulic jack hammer, and various others. It is typical that such attachments are able to be remotely and hydraulically coupled to the coupler via two parallel connecting pins on the attachments. The coupler is a key part of equipment for an excavator and an excavator operator can change attachments many times per day.
A critical aspect of working in the excavator industry is safety. While many couplers for coupling attachments have been described such as that described in WO2014/098616 the system described is complex and involves many moving parts and linkages that are vulnerable to failure. Because of its complexity the system described in WO2014/098616 is more likely to be used on large couplers rather than small coupling systems. The complex coupling systems are more difficult to maintain and more expensive to produce, which introduces economical barriers for businesses. There is also more opportunity for components to fail and for the safety of the coupler to be compromised.
It is therefore an object of the present invention to provide a coupler which is simple to produce and which will continue to lock onto the attachment even in the event of a hydraulic cylinder failure, or to at least provide the public with a useful choice.